Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
  • C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
  • C08L23/10—Homopolymers or copolymers of propene
  • C08L23/12—Polypropene
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
  • C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
  • C08L23/10—Homopolymers or copolymers of propene
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
  • C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
  • C08L23/10—Homopolymers or copolymers of propene
  • C08L23/14—Copolymers of propene
  • C08L23/142—Copolymers of propene at least partially crystalline copolymers of propene with other olefins
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L51/00—Compositions of graft polymers in which the grafted component is obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers
  • C08L51/06—Compositions of graft polymers in which the grafted component is obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers grafted on to homopolymers or copolymers of aliphatic hydrocarbons containing only one carbon-to-carbon double bond
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L2205/00—Polymer mixtures characterised by other features
  • C08L2205/02—Polymer mixtures characterised by other features containing two or more polymers of the same C08L -group
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L2205/00—Polymer mixtures characterised by other features
  • C08L2205/03—Polymer mixtures characterised by other features containing three or more polymers in a blend
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
  • C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
  • C08L23/18—Homopolymers or copolymers of hydrocarbons having four or more carbon atoms
  • C08L23/20—Homopolymers or copolymers of hydrocarbons having four or more carbon atoms having four to nine carbon atoms
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L45/00—Compositions of homopolymers or copolymers of compounds having no unsaturated aliphatic radicals in side chain, and having one or more carbon-to-carbon double bonds in a carbocyclic or in a heterocyclic ring system; Compositions of derivatives of such polymers

Definitions

• the present invention regards propylene homo- and co-polymers grafted with polyalkenylenes and process for preparing them by reactive transformation of the homo- or co-polymer of polypropylene in the presence of polyalkenylene and particular non-peroxide radical initiators.
• Japanese patent 58-090291 describes the use of alkyl and bromo derivatives of 1,2-diphenylethane as radical initiator in the controlled degradation process of propylene polymers.
• the polymers obtained show good rheological properties; yet at the same time the mechanical properties, in particular the impact strength, are worsened.
• Modifying crystalline propylene polymers by treating at temperatures comprised between 250 and 300°C with ⁇ -olefin polymers and copolymers, for example 1-butene, in the presence of a peroxide radical initiator is also known from European patent 261,786. Even operating in this way the modified product obtained does not show improved impact strength properties and in addition the presence of the peroxide initiator can give rise to secondary crosslinking reactions of the polymer.
• the polymers of the invention can be prepared by a new process of reactive transformation of the propylene homopolymer and copolymer in such a way that the fluidity is increased without incurring reduction of the impact strength properties which is verified in the conventional process of degradation for obtaining polymers with controlled rheology.
• the process of the invention comprises a thermal treatment, at a temperature comprised between 200-350°C, of a propylene polymer with reactive polyalkenylenes in the presence of non-peroxide radical initiators.
• propylene polymer Both homopolymers and copolymers of propylene are referred to with the term propylene polymer.
• they comprise: (co)polymers with a isotactic index of higher than 80%; crystalline copolymers with small amounts of one or more ⁇ -olefins having 2-10 carbon atoms, for example ethylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-octene; impact strength polypropylene compositions obtained through sequential polymerisation of propylene and its mixture with ethylene and/or ⁇ -olefins; syndiotactic propylene polymers; blends of isotactic polypropylene with EP(D)M.
• the propylene polymers have Melt Flow Index (MFI) values generally comprised in the range from 0.1 to 100, preferably between 0.2 and 50 at 230°C/21.6 N (according to ASTM 1238 L).
• MFI Melt Flow Index
• the reactive polyalkenylene have a trans double bond content generally higher than 30% (calculated with respect to the total number of double bonds present in the polyalkenylene chain) and preferably comprised between 35 and 80%.
• the polyalkenylene used is a polyoctenylene having a content of trans double bonds higher than 60%.
• These compounds can be prepared by metathesis reaction starting from cyclooctene. Examples of these compounds are trans Octenamer Rubber (TOR), commercialised by Chemische Werke Huels AG with the name Vestenamer 8012 and Vestenamer 6213.
• Other examples of suitable polyalkenylene for use in the process of the invention are trans-polyhexanamers obtained by copolymerization of butadiene and ethylene with a vanadium catalyst.
• the quantity of polyalkenylene used in the process of the invention can vary within a large range; generally the quantity is less than 20% by weight and preferably comprised between 0.1 and 10% by weight.
• the non-peroxide free radical initiators used in the process of the invention may be selected from, for example, alkyl derivatives of 1,2-diphenylethane and silylbenzopinacole derivatives. Good results are obtained with the use of 2,3-dimethyl-2,3-diphenylbutane (commercialised as Interox CCDFB by Peroxyd Chemie) also for 3,4-dimethyl-3,4-diphenyl hexane (commercialised as Interox CCDHF by Peroxyd Chemie) and oligomers of 1,3- and 1,4-diisopropyl benzene.
• 2,3-dimethyl-2,3-diphenylbutane commercialised as Interox CCDFB by Peroxyd Chemie
• 3,4-dimethyl-3,4-diphenyl hexane commercialised as Interox CCDHF by Peroxyd Chemie
• oligomers of 1,3- and 1,4-diisopropyl benzene commercialised
• the amount of non-peroxide radical initiator to be used in the process of the invention may vary within a wide range according to the effect that one wants to be obtained and, in general, is comprised between 0.05 and 3% by weight of the polymer, preferably between 0.1 and 1% by weight.
• the process of the invention is carried out in the presence of antioxidants and stabilisers.
• Any primary and secondary antioxidising agent conventionally used can be used as antioxidant agents.
• sterically hindered phenols can be mentioned, preferably 2,6-di-t-butyl-4-methylphenol (BHT), Secondary aromatic amines, thioethers, phosphites, phosphonites, zinc dithiobutylcarbamate and their mixtures.
• BHT 2,6-di-t-butyl-4-methylphenol
• Secondary aromatic amines thioethers
• phosphites phosphites
• phosphonites zinc dithiobutylcarbamate and their mixtures.
• BHT 2,6-di-t-butyl-4-methylphenol
• phosphonites zinc dithiobutylcarbamate and their mixtures.
• BHT 2,6-di-t-butyl-4-methylphenol
• phosphonites zinc dithiobutylcarbamate
• zinc dithiobutylcarbamate zinc dithiobutylcarbamate
• the antioxidants are generally used in amounts not higher than 2% by weight, preferably between 0.01 and 1% by weight.
• UV stabilisers such as UV stabilisers, nucleating agents, lubricants, flame-retardants etc can be also be added to this compound.
• talc talc
• mica talc
• calcium carbonate talc
• reinforcing agents such as for example glass fibre.
• the restructuring process through grafting with polyalkenylene occurs at a temperature comprised in the range of 200-350°C, preferably in the range of 270-330°C.
• the restructuring process may be carried out by heating to a suitable temperature for a period of time generally comprised between 0.1 and 20 minutes, preferably between 0.5 and 10 minutes, operating in a conventional ram mixer, for example Banbury type, or preferably in an extruder.
• the polyalkenylene can be added in powder form or as granules together to the radical initiator and the propylene polymer, or under the form of concentrated masterbatch of polymer directly introduced into the extruder together with the (co)polymer to be restructured.
• composition to be restructured can preferably be subjected to a preliminary hot mixing at a temperature comprised between 220 and 240°C and subsequent treatment at the reaction temperature indicated.
• This reaction may be advantageously carried out during the transformation process of the (co)polymer via injection moulding.
• propylene polymers may be subjected to a preliminary degradation reaction in the presence of the previously mentioned radical generators at a temperature of 270-330°C.
• the polyalkenylene is then added to the so obtained product and subjected to restructuring reaction at a temperature comprised between 200 and 250°C.
• the radical generators as well as the antioxidants can be added beforehand during the synthesis of the propylene polymer.
• the polyalkenylene is then added to the so obtained (co)polymers and then subjected to the restructuring reaction.
• the process of restructuring leads to an increase in Melt Flow Index of the polymer and at the same time a marked increase in the impact strength of the articles so obtained.
• the mixture was fed in the hopper of a single screw extruder of the Dolci type with a thread of 45 mm and then extruded operating at a head temperature of 285-290°C, with a load of about 10 Kg/hour, a screw speed of 50/60 revolutions per minute and a stay time of about 200 seconds.
• the mixture went to granulation and from the granules standard bars having a thickness of 3 mm were obtained by injection moulding in a Negri and Bossi injection moulding press 225-640 N (with a barrel having a diameter of 50 mm and a free die), operating at a melt temperature of 230-240°C and a specific pressure of 980 bar.
• the die was thermostated at a temperature of 30°C.
• the total energy at breakage was determined according to the ball drop method. For this reason disks having a diameter of 100 mm and a thickness of 3 mm were injection moulded. The test has been carried out operating with a beam having a hemi-spherical head of diameter equal to 20 mm, with a clear span diameter of the support of 60 mm and an impact speed of 5 m/sec, with instruments according to the norm for DIN 53443 part 2 a .
• the initial mixture comprises 10 parts by weight of poly trans Octenamer Rubber having an average molecular weight of 1.0 ⁇ 10 ⁇ 5, a cis/trans double bond ratio equal to 80:20, commercialised by Huels AG in the name of Vestenamer 8012.
• polypropylene Moplen YD 50 G 5Kg of polypropylene Moplen YD 50 G is mixed in a Henschel turbomixer with 0.1% by weight of BHT and 0.1% by weight of Irganox 1035. Then non-peroxide radical initiator Irganox CCDFB (0.6% by weight), calcium stearate (0.1 % by weight) and 0.5% by weight of Vestenamer 8012 are added.
• the composition is then subjected to mixing in a mixer with a co-rotating Werner Pfleider screw at a temperature of 220-240°C and then granulated.
• the product obtained is then subjected to injection moulding at a temperature of 280-290°C.
• the specimens obtained are characterised according to what was described in example 1 and the results are reported in Table 1. Comparing the data obtained with those of example 3, it can be seen that for the same MFI the mechanical properties of impact strength are markedly improved. In addition the resulting specimens obtained are completely transparent whilst the specimens from example 3 show opalescent.
• Moplen YD 50 G To 95 parts by weight of Moplen YD 50 G, 5 parts by weight of a masterbatch consisting of Moplen YD 50 G (87.97% weight), Interox CCDFB (12% weight), BHT (0.1% weight), Irganox 1035 (0.1% weight) calcium stearate (0.1% weight) are added. The mixture is then extruded at 280-290°C and granulated. To 100 parts by weight of this product, having an MFI equal to 20, a subsequent addition of 5 parts by weight of vestenamer 8012 are added. After mixing in a tumbler, the injection moulding is carried out at a temperature of 230-240°C. The mfi values and the mechanical properties are reported in Table 1.
• ethylene/propylene copolymer (containing 5% by weight of ethylene) commercialised by Himont Italia as Moplen EPD 60 R, having a MFI equal to 0.35 dg/min, are mixed in a Tumbler with 0.1% by weight of BHT antioxidant, 0.1% by weight of Irganox 1035, 0.1% by weight of calcium stearate. 0.6% by weight of Interox CCDHF is then added. 5 parts by weight of poly trans Octenamer Rubber, having an average molecular weight of 1.2 ⁇ 10 ⁇ 5 and a trans/cis double bond ratio of 60:40 and commercialised by Huels AG as Vestenamer 6213, is then added to the composition.
• composition so obtained was subjected to extrusion at 290°C. Subsequently the copolymer is compression moulded at 240°C and the specimens so obtained were used for the determination of the mechanical tests as described in example 1. The results obtained are reported in table 1.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Crystallography & Structural Chemistry (AREA)
• Graft Or Block Polymers (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
• Laminated Bodies (AREA)
• Processes Of Treating Macromolecular Substances (AREA)
• Polyoxymethylene Polymers And Polymers With Carbon-To-Carbon Bonds (AREA)

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Publications (3)

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• 1993
  • 1993-05-13 IT IT93MI000975A patent/IT1264437B1/it active IP Right Grant
• 1994
  • 1994-05-04 EP EP94106968A patent/EP0624622B1/fr not_active Expired - Lifetime
  • 1994-05-04 ES ES94106968T patent/ES2128455T3/es not_active Expired - Lifetime
  • 1994-05-04 DK DK94106968T patent/DK0624622T3/da active
  • 1994-05-04 AT AT94106968T patent/ATE176266T1/de not_active IP Right Cessation
  • 1994-05-04 DE DE69416189T patent/DE69416189T2/de not_active Expired - Fee Related
  • 1994-05-09 US US08/239,712 patent/US5480942A/en not_active Expired - Fee Related
  • 1994-05-10 JP JP09670394A patent/JP3414490B2/ja not_active Expired - Fee Related
• 1997
  • 1997-05-23 US US08/862,332 patent/US5859139A/en not_active Expired - Fee Related

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